Process for producing magnesium carbonate



STATES PATENT OFFICE.

y CARL CIR-AMER, OF ZURZACH, SWITZERLAND, ASSIGNOR TO THE CHEMISCHEEABRIK GRIESHEIM-ELEKTRON, OF FRANKFORT-ON-THE-MAIN, GERMANY.

cuts,

' Lewis". Specification of Letters Patent. t t u 29, 1 22 Applicationfiled Jnne12, 1922. Serial No. 567,739.

PROCESS FOR PRODUCING MAGNESIUM CARBONATE.

No Drawing.

process of producing carbonates of magnesium, and it is intended tofacilitate the precipitation thereof by ammonium carbonate.

When ammonium canbonate is added to a dilute solution of a magnesiumsalt, no pre cipitation is produced, the precipitationsv only takingplace upon heating the mixture to a temperature of about 50 degree C.

According to my experiments, however, a

quantitative precipitation is obtained if the addition'of ammoniumcarbonate is made to magnesia liquors containing other constituthus forinstance to the spent liquors obtained in the manufacture of potassiumsalts, and containing chiefly com ounds. It has been found that, if theprecipitant is added to magnesium solutions of the kind referred to, andof which the mother liquors of theStassfurt salts, and of similardeposits, are a typical instance, precipitation of carbonate will occurwithout exterior heat, and particularly if the mixture is submitted to amechanical agitation involving interior mechanical work, and theaccompanying interior heat. By this means the necessary interior energyis produced whereby this reaction for practical purposes becomes, so tospeak, exothermic. Thismechanical labor is, preferably furnished bymeans of a turbine or similar motor which or homogenization devices aretion of magnesium carbonate becomes highly ing of fuelaand of wages; andit has been suggested heretofore forcthe homogenization of mixtures ofdifiicultly miscible substances of different degrees or stages ofsolidity and surface tension, as an instance in United States Patent No.1,387,832, dated August'16, 1921 and granted to Otto F. Brumann. Suchturbines driven by a motor engine icomprismg one or more rotors.

By proceeding in this manner the'produceconomical, particularly asregards. the savdegrees magnesium the old method and as disclosedpreferably is consider-'- ated by a motor engine with one or morerotors. After the turbine has been operated for about 15 minutes theliquid is run off and'fi'lt'ered, in order to separate it from theprecipitate which has the formula MgCO H O, which is then dried. Fromthe neutral carbonate thus produced, basic carbonate may be obtained bydispersing the wet product obtained in suspension in an appropriatequantity of water heatdto about 40 to 0., the mixture being thenintroduced into a kind described. By working the turbine for some timethe magnesium carbonate will be converted into basic magnesium carbonatewith the liberation of carbon dioxide which escapes into the atmosphere.This conversion is going on very rapidly and at a quantitative rate.reaction is exceedingly fiufl'y or voluminous,

and in this respect possesses all the desirable qualities'required y theconsumers.

The new method of treatment according to this invention is not limitedto magnesium carbonate of theparticular kind and sources hereinbeforereferred to, but it may also be carried out and utilized to aid in theprecipitation of magnesium carbonate from solutions. of other sources aswell. Particularly as regards the preparation of the basic carbonate, itis greatly superior to the old method, and much more economical,inasmuch as which, on account of the consumption of'fuel, is ratherexpensive, requires the boiling of the suspended magnesium carbonatewith water for a oomparain order to split ofi part of tively long time,the carbon dioxide.

In the practice of this partof my inven-' tion- I may, for instance,proceed as follows:-,-

A mixture consisting of 50 kilo ams'neutral, magnesium carbonate (Mg 3110). free from the mother liquors of its production, and of 5000kilograms of water is submitted for about ten minutes to the action of aturb'ne, as above described, at a te id temperature of about fortydegrees The The final'product of the homogenization device of the g'carbonates, which consists in mixture is then filtered, and a productis obtained containing44% MgO and 36% CO and consisting of basicmagnesium carbonate in accordance with the formula 2- 4MgO.3C0 .4H O.

- It will be understood that by the-term homogenization as usedherein ismeant intense mechanical agitation.

I claim 1. The process of producing carbonates of ammonium carbonatewith soluble magnesium salts, which mixture to agitation.-

2. I11 the process of producing magnesium carbonates, treating motherliquors from potassium carrying magnesium salts with ammonium carbonateas the precipitating agent, and submitting the mixture to agitation.

3. In the process of producin magnesium carbonates, treating solutions 0magnesium salts with ammonium carbonate, and submitting the mixture attepid temperature to agitation untilabasic carbonate is precipitatedwith the evolutionof carbondioxide.

4. The process of producing magnesium treating the mother liquors ofpotassium carrying magnesium salts with ammonium carbonate, submittingthe mixture 'to agitation and con tinuing the treatment until carbondioxide is evolved and basic carbonate is precipitated.

5. The method of producing magnesium magnesium by mutual decompositionof,

comprises submitting the to the action of ammoniumcarbonate, and'intensely agitating the mixture by means of aemotor driven turbinepossessing one or more rotors.

6. The method of producing basic magnesium carbonate from magnesiumsalts which consists in treating a solution of spent liquors from themanufacture of potassium salts, and containing magnesium salts withammonium carbonate, agitating the mixture, and agitating the ensuingprecipitate with water at a temperature of from 40 to 50 degrees bymeans of a motor driven turbine possessing one or more rotors.

7. The process of producing magnesium carbonate which comprises treatingsolutions of magnesium salts bonate and intensely agitating the mixturefor a period of about fifteen minutes and filtering out the precipitate.

8. The process of producing magnesium carbonate which comprises treatingsolutions of magnesium salts with ammonium carbonate, agitating themixture for a period of about fifteen minutes, then again agitating.

the ensuing preci itate free from mother liquors with tepi about tenminutes.

In testimony whereof I affix my si nature.

CARL ORA ER. Witnesses:

J ..A. DURST, D. W. KAPPELER,

water for a period of with ammonium car-

